UPDATE 8.40PM: Endeavour Energy says many homes will remain without power overnight, due to unsafe conditions.
Customers who need power for medical equipment should check their battery supply and consider acting on their back up plan.
Crews are responding to power outages affecting 18,000 homes and businesses due to tonight's storm.
"Damage to the electricity network is located mainly in the Illawarra, Shellharbour and on the South Coast," a spokesperson said.
"In these areas, crews are patrolling damaging parts of the network to make safe and switch around fault sites to safely restore customers as quickly as possible.
"Extra crews are being marshalled to assist with the repair efforts, with over 250 hazardous incidents to investigate. It is likely that due to the damage that some customers will be without power overnight."
If you must go outside, stay at least eight metres away from fallen power lines - especially where trees have been brought down over powerlines.
A fallen tree is affecting northbound traffic on the Princes Motorway near Mount Ousley Road.
EARLIER: More than 7000 homes south of Wollongong are without power, as wild weather batters the region.
An Endeavour Energy spokesperson confirmed that 1366 homes in Barrack Heights, 1076 homes in Lake Heights, 899 homes in Jamberoo, 804 homes in Warrawong, 714 homes in Albion Park, 637 homes in Tullimbar, 627 homes in Kiama Downs, 533 homes in Shellharbour, 422 homes in Kiama, 276 homes in Shell Cove and 269 homes with Barrack point had been cut off.
"We've got crews on the way trying to get people connected as safely and quickly as possible, but there are pretty wild conditions out there," the spokesperson said.
There is currently a severe weather warning in place for the region.
The Bureau of Meteorology has warned of damaging winds averaging 60 to 70 km/h with peak gusts in excess of 90 km/h.
The Illawarra Highway is closed in both directions on Macquarie Pass due to high winds and fallen trees.
Motorists are advised to avoid the area.
Motorists in light vehicles can use Jamberoo Mountain Road as an alternative route.
Heavy vehicles need to use a longer diversion via the Hume Highway, Picton Road and the M1 Princes Motorway.
Parts of the coastline facing south can expect destructive wind gusts of about 120km/h.
Winds are expected to gradually ease below gale or damaging wind thresholds during Wednesday morning as the low slowly tracks into the Tasman Sea.